Refrigerating system and valve construction



May 9, 1961 INVEN TOR THaMAs E. NOAKES A TTORNEVS REFRIGERAI'ING SYSTEM AND VALVE coNsrRUcrroN Thomas Edmund Noakes, Detroit, Mich, assignor to American Radiator & Standard Sanitary Corporation,

New York, N.Y.,- a corporation of Delaware Filed July 9, 1957, 'Ser. No. 670,740

8 Claims. (Cl. 62-278) This invention relates to a valve construction useful for controlling fluid flow in a refrigerating system so as to aid in the periodic defrosting of the evaporator coils.

Objects of the invention are to provide a refrigerating system and valve construction wherein:

(1) Defrost of the evaporator coils is quickly performed by means of a single valve device without any deleterious effects on the refrigerant compressor, and

(2) The valve device is of simple, low cost construction.

Other objects of thisinvention will appear in the following description and appended claims, reference being had-to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

Fig. 1 is a schematic view of a refrigerating system (with a valve device employed therein shown in section) constructed according to the invention.

Fig. 2 is a sectional view of a second valve which may be employed in the Fig. 1 refrigerating system in place of the Fig. 1 valve.

Fig. 3 is a sectional view of another valve which may be employed in the Fig. 1 system in place of the Fig. 1

valve.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and f being practiced or carried out in various ways. Also, it is to be understood that thephraseology or terminology employed herein isfor' the purpose of description and not of limitation.

In Fig. 1 of the drawings there. is shown a refrigerating system which includes a refrigerant compressor 1, condenser 2, receiver 3, evaporator 4, and capillary tubing 5. During normal operation of the system'gaseous refrigerant is compressed to a superheated vapor in compressor 1 and liquified in condenser 2. The liquid refrigerant is passed from receiver 3 through capillary tubing 5 so as to be restricted in its flow into evaporator 4 in such manner as to vaporize and extract heat from the atmosphere surrounding the evaporator coil. The vaporized refrigerant is discharged into a suction line 6 from where it is drawn into compressor 1 so as to repeat the cycle. Bypass line 7 is closed by valve mechanism 8 during normal operation of the system. By-pass line 9 has incorporated therein a length of capillary tubing 10 which acts to prevent all but a small amount of the refrigerant from flowing through line 9 during normal operation.

Defrost of the evaporator coil is accomplished by actuation of valve mechanism -8. This valve mechanism includes a housing 11 which is bored out at 12 and 13 to provide two chambers separated by an interior wall 14.

An orifice 15 formed in wall 14 is opened and closed by a plunger 16 which is slidably mounted for limited movement in an armature 17. Energization of solenoid coil 18 lifts armature 17 upwardly in sleeve 19 so as to strike ring 20 on plunger 16 and carry the plunger upwardly away from orifice 15, the arrangement being such as to develop a high impact force on plunger 16 with low curat' the juncture between bore 13 and counterbore 27.

Tube 29, which'forms part of suction line 6, is soldered in place in fitting 26. Tube 30, which forms another part of the suction line, is soldered in place within an opening 31 drilled into the side wall of chamber 13. Tube 2, which forms part of by-pass line 7, is soldered in place within an opening 33 drilled into the side wall of chamber 12; The design ofvalve mechanism 8 is such that housing 11 can be formed by economical die casting and boring operations. Only the single insert 26 need be provided to complete the housing.

During the normal refrigerating cycle plunger 16 is in its illustrated position (with solenoid 18 deenergized) so that spring 25 is effective to force element 24 away from fitting 26 in such manner as to permit vaporized refrigerant from evaporator 4 to flow through suction line 6 to compressor 1.

When is is desired to defrost the evaporator coils solenoid 18 is energized to move plunger 16 away from orifice 15. Liquid refrigerant from line 7 flows through orifice 15 'into the space within piston 21 so as to develop a downward pressure on the piston which is effective to force element 24 into a position closing the port formed by fitting 26. Pressure development on piston 21 is facilitated by the small area of opening 22 which causes the pressure above the piston to necessarily be greater than the pressure below the piston.

With fitting 26'closed to flow the liquid refrigerant from orifice 15 flows into tube 30, through evaporator 4, line 9 (including capillary tubing 10), portion 34 of line 6 and into compressor 1. After the refrigerant passes capillary tubing 10 it is expanded to the vapor state so that it does not overload the compressor. During its passage through the evaporator the refrigerant extracts heat from the atmosphere surrounding the evaporator coil so as to melt any ice accumulations on the coil surfaces.

If desired valve mechanism 8 may be replaced by the valve mechanism shown in Fig. 2. In the Fig. 2 mechanism valve housing 11' includes two stamped metal housing sections 40 and 41 heliarc welded together at 42. Sections 40 and 41 are fixedly secured on the lower end ofa die cast housing section 43, and a corrugated metal diaphragm 21 is positioned between sections 40 and 41 so as to have its upper face in communication with orifice 15'. a

The diaphragm is provided with a bleed opening 22' having a function similar to that of opening 22 in the Fig. 1 valve mechanism. The lower face of diaphragm 21' is backed up by a fixed annular plate 44 which serves to prevent excessive diaphragm flexing. The central portion of diaphragm 21 carries a circular disc element 24' which opens and-closes a port formed by the upper end of tube 29. A compression spring 25' urges disc element 24' and diaphragm 21' away from the port.

In operation of the Fig. 2 device, during normal use of the system plunger 16 is in its illustrated position.

Patented May 9, 1961 vated position such as to open" orifice 15'.v Refrigerant.

from receiver 3 (shown in Fig. 1) flows into the valve through tube 32, where it pressures against diaphragm 21' so as to force said diaphragm downwardlyagainst the action of spring 25'. Downward movement of the diaphragm causes disc element 24' to close tube 29'. The refrigerant above diaphragm 21-is forced through openiiig 22' and eventually into tube 30, where it passes through the evaporator and by-pass line 9 (Fig. 1) back to-the compressor so as to defrost the evaporator coils in the-same manner as outlined in the previous descriptionof the Fig. .1 arrangement.

' If desired bleed opening 22' could be omitted in lieu of a bleed opening 48 and by-pass line 49 connected into tube3'0 as indicated in dotted lines in Fig. 2. Either construction is effective to give the desired cycle of operation. Y

.I claim: V

l. The combination comprising a housing structure having a movable wall .therein subdividing the structure into two separate chambers; a first line adapted to feed high pressure fluid into one of the chambers; valve means opening and closing the line to control the application of high pressure fluid intosaid one chamber; a second line normally feeding low pressure fluid into the other of said chambers; a third line normally receiving low pressure fluid from the other chamber; a valve element operated by the movable wall to close off the third line from the other chamber in response to the admission of high pressure fluid into said onechamber; and a passageway between said one chamber and the second line; whereby when the valve means is open the high pressure fluid is enabled to (1) flowinto said one'chamber, (2) force the valve element to a position closing the third line, and

spring means operating on the movable against the action of the high pressure fluid to ensure opening of the third line upon closing of the valve means.

7. The combination of claim 1, wherein the passageway is of smaller size than theetfective size of the first line; whereby when the valve means is open a pressure difierential is established between theone chamber and the second line.

8. A refrigerant circuit comprising a compressor; a

condenser; an evaporator; a suction line between the evaporator and compresor; an evaporator inlet line from the condenser including a first flow restrictormeans; a first by-pass line from the condenser to the suction line and around the flow restrictor means; a second by-pass line between the evaporator inlet, line and compressor, said second by-pass line having a second flow restrictor means therein; and valve means for alternately (1) opening the first by-pass line to the portion of the suction line connected with the evaporator while closing the portionof the suction line connected to the compresor to putthe evaporator in the high side of the circuit, and (2) closing the first by-passline while opening the suction line to 7 put the evaporator in the low side of the circuit; said valve means comprising a housing means having a movable wall therein subdividing said housing means into first and second chambers, said housing'means'being connected into the circuit with thefirst chamber serving 1 as part of the suction line and with the movable wall closably registering with the portion oi the suction :line connected to the compressor, spring means acting on the movable wall to normally hold said wall away from said compressor-connected portion of, the suction line, said housing means being connected into the circuit with-the (3) flow from said onechamber into the second line; 7

and whereby when the valve means is closed the low pressure fluid from the second lineis enabled to flow means is positioned directly. atop the housing structure to cooperate therewith in forming a unitary assembly.

6. The combination of claim 1 and further-comprising second chamber in fluid communication with thefirst by-pass line, an electrically-operated valve element for opening and closing said first by-pass line tosaid second chamber, and passage means continuously inter-connecting said first and second chambers, whereby, when said valve element is in the open position the fluid pressure in said second chamber is eifective to force the movable wall to a position closing the compressor-connected portion of the suction line.

References Cited in the file of this patent UNITED STATES PATENTS Y 2,080,288 McCormaek May .11, 1937 2,451,385 Great Oct. .12, 19.43 2,579,439 Noe Dec. 18, 19.51 2,631,441 Shoemaker Mar. 17, 1953 2,675,684 Shoemaker Apr. 20, .1954

Zearfoss May 18, 1954 

